The biological process of neovascularization (otherwise known as angiogenesis, the formation of new blood vessels) is necessary for normal development and is also an important aspect of wound repair, pathological conditions like inflammation, and solid tumor growth (Leibovich et al., 1988, in "Growth Factors and Other Aspects of Wound Healing," Barbul et al., eds., Alan R. Liss, N.Y. p. 132). The angiogenic cascade involves endothelial cell migration, protease production and endothelial cell proliferation (Leibovich et al., supra). Many well known and variously characterized autocrine and paracrine growth factors are involved in the angiogenic cascade. One of the lesser characterized factors is Platelet Derived Angiogenesis Factor (PDAF; Banda et al., 1982, Proc. Natl. Acad. Sci. 79:7773-7777).